2.19 for a k+−cl− ion pair, attractive and repulsive energies ea and er, respectively, depend on the distance between the ions r, according to e a = − 1.436 r e r = 5.86 × 10 − 6 r 9 ea=−1.436rer=5.86×10−6r9 for these expressions, energies are expressed in electron volts per k+−cl− pair, and r is the distance in nanometers. the net energy en is just the sum of the preceding two expressions. (a) superimpose on a single plot en, er, and ea versus r up to 1.0 nm. (b) on the basis of this plot, determine (i) the equilibrium spacing r0 between the k+ and cl− ions, and (ii) the magnitude of the bonding energy e0 between the two ions.